Firefox 3 has private browsing features built right in, but if you're running an older version it doesn't mean you have to give up your privacy altogether. Here are five Firefox extensions that will keep your browsing discreet and private no matter what version of Firefox you're using:

TrackMeNot - This extension runs in the background as you browse and periodically sends out random queries to search engines so your actual searches get lost in the crowd. Your search activities stay hidden so sites like Yahoo! and Google won't be able to gather any meaningful data from your visit.

Unless you've been living in a cave for the past year, you know that microblogging is all the rage. Web sites like Twitter, Identi.ca, and Laconica are incredibly popular for exchanging snippets of information, chatting with others, and quickly sharing links to interesting online content. It's really a pain to jump from site to site to read your friends updates or provide your own, so here are five microblogging extensions for Firefox to help you out.

ShortenURL - Microbloggers don't want to waste precious characters on long URLs so it's customary to shorten links you display in status updates. Pasting a Web site location into URL shortening service homepage is so last week now that you can do it right from your browser's toolbar. ShortenURL makes quick work of this repetitive task by letting you crop Web addresses right from the toolbar. It supports over 100 URL shortening services already but if that's not enough, you can request more.

Recently, we covered Mozilla's overhauled version of Jetpack, which is designed to make it easy for almost anyone to create Firefox extensions. Jetpack is one of several initiatives from Mozilla focused on the main advantage that Firefox has over other browers: the huge ecosystem of outstanding add-ons. Today, Mozilla's Firefox Add-Ons Lead Nick Nguyen and his team have announced the Contributions Pilot Program. It's a way for developers to better showcase themselves next to their Add-ons, as well as be eligible to receive a suggested contribution for their work through PayPal.